<!DOCTYPE html>
<html lang="en">
<script src="../js/vue.js"></script>

<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="app">
<h2 v-once>{{n}}</h2>
<button @click="add">addd</button>
    {{n}}
<div v-text="name"></div>

</div>
</body>
<script type="text/javascript">
    const  vm = new Vue({
        el:"#app",
        data:{
            name:'charzhan',
            n:1,
        },
        methods:{
          add(){
              this.n++
          }
        }
    })
</script>
</html>